Cereal Leaf Beetle

I have not had specific reports but cereal leaf beetle seems to be more prevalent the past few years and something you may not have seen. The following information appeared in the last issue of Crop Observation and Recommendation Network Newsletter.

Reports of the insect being more active than usual in lower central Michigan and other locations in northern Ohio. All of this suggests that wheat growers should begin scouting their fields for potential problems.

Of more importance is the cereal leaf beetle threshold. Ohio has historically used an average of 2 or more larvae per stem as the economic threshold, the time when an insecticide application should be considered. This has been in effect for the past 30-40 years, during which the cereal leaf beetle has not been a major concern. We have recently searched the literature on cereal leaf beetle thresholds on wheat from many wheat growing states, including some of our neighboring states. It became evident that our threshold is perhaps too high; most if not all the other states have a lower threshold of one larva per stem or flag leaf. Thus, we believe it appropriate to lower the threshold for cereal leaf beetle in Ohio to one larva per stem or flag leaf.

As mentioned last week, insecticides for control are available at http://entomology.osu.edu/ag/images/sgiclb.pdf . And for organic growers, remember that Entrust is a spinosad product that is permissible on organic crops, being that it is OMRI listed.